Typically, a drop wire clamp assembly is used to support the telephone drop wire which is an insulated telephone cable which is strung between a pole and a building. The drop wire clamp assembly has a wire or cable which attaches to the structure so as to bear the weight of the suspended telephone drop wire where the telephone cable reaches the building or telephone pole. The clamp assembly should firmly grip and hold the drop wire even under great tension. However, the grip must be made without breaking or cutting the insulation of the drop wire, which could cause failure of the telephone service.
Drop wire clamp assemblies typically comprise a wedge-shaped bail housing having a series of ridges, and a wedge-shaped slide which mates with the housing to locate the insulated drop wire therebetween. A wire loop extends from the wedge slide for connection to the structure. The bail housing and wedge slide are all formed of stainless steel or other metal. A shim or pressure pad having a large number of perforations may be located between the wedge slide and the drop wire, and may have retaining ears which prevent the shim from moving longitudinally. As the wedge slide is slid to the bail housing, the shim presses into the insulation of the drop wire to firmly grip and hold the drop wire.
While the foregoing technique is suitable for many types of wires and lines, it is less desirable for use with certain reinforced lines. These reinforced lines are used when a line must span a long distance between supporting members, such as poles. In such long spans, conducting wires alone cannot withstand the tension forces caused by their own weight. Thus, a thin metal support member or cable is provided to reinforce the conducting wires. In the twin or "figure eight" configuration, these reinforced lines have a number of conducting wires which are contained in a first cylindrical insulating sleeve, and a thin metal support wire which is contained in a second cylindrical insulating sleeve. The two insulating sleeves are integrally joined, so that the cross-section of the reinforced line has a figure eight shape. The term "figure eight wire" or "figure eight drop wire" as used herein refers to reinforced line having a configuration as described above.
When the above-described drop wire clamp assembly is used to clamp a reinforced line, such as a figure eight wire, the presence of the support wire creates several problems. First, the support wire makes the line bulky and cumbersome to handle when applying the clamp. Second, the thickness of the support wire reduces the effectiveness of the clamp. Third, the support wire, when inserted into the clamp with the conducting wires, tends to crush the conducting wires, thereby increasing the chances of a short circuit or other failure.
Ideally, a drop wire clamp suitable for figure eight drop wires should clamp the support line without clamping the conducting wires.